MSK neoplasms

Question 1

neoplasms that usually localizes in the facial bones and nasal sinuses

Answer 1

Osteoma

Question 2

complications of an osteoma

Answer 2

sinus obstruction

congestion

pressure headaches

Question 3

Difference between osteoid osteoma and osteoblastoma

Answer 3

osteoid osteoma

• < 2cm
• diaphysis of long bones
• Appendicular skeleton

Osteoblastoma

• >2cm
• axial skeleton

Question 4

Describe the morphology of an osteoid osteoma

Answer 4

well-circumscribed round/ oval mass in the cortex of long bones

hemorrhagic, tan/ gritty tissue with haphazard interconnections of woven trabeculae rimmed by osteoblasts

Intertrabecular spaces are filled by vascularized loose connective tissue

Question 5

Clinical presentation of osteoid osteoma

Answer 5

severe nocturnal pain that is relieved with ASA

Question 6

Osteoblastoma clinical presentation

Answer 6

dull pain that is unresponsive to ASA

Question 7

Most common primary malignant tumor of the bone

Answer 7

Osteosarcoma

Question 8

Associations of Osteosarcoma

Answer 8

RB

TP53

INK4a

MDM2

CDK4

Paget Disease

Bone Infarcts

Prior radiation

Question 9

Diagnostics of osteosarcoma

Answer 9

appears at the metaphyseal region of long bones

tumor frequently breaks through the cortex and lifts the periosteum, forming a sunburst appearance and Codman’s triangle

Question 10

Morphology of osteosarcoma

Answer 10

gritty, grey-white areas of hemorrhage and or cystic degeneration

fine lacelike pattern of neoplastic bone replaced by anaplastic malignant tumor cells

broad sheets or primitive trabeculae

Question 11

Clinical presentation of osteosarcoma

Answer 11

painfully aggressive enlarging masses in long bones

usually around the knee

Question 12

2nd most common group of bone sarcomas in children

Answer 12

Ewing Sarcoma

Question 13

Pathology of Ewing Sarcoma

Answer 13

t(11q24; 22q12) causes the fusion of EWS gene on chromosome 22 to the FLI1 gene

Question 14

Diagnostics of Ewing sarcoma

Answer 14

appears at the diaphysis of femur, tibia and flat bones of the pelvis

Destructive lytic tumor with permeative margins that extend into the surrounding soft tissues

Periosteal reaction- layers of reactive bone

Question 15

Morphology of Ewing Sarcoma

Answer 15

soft, tan/white areas of hemorrhage and necrosis

sheets of small uniform, round cells with scant cytoplasm

cytoplasm appears clear due to abundance of glycogen

Homer wright rosettes

Question 16

Ewing Sarcoma Clinical Presentation

Answer 16

painful enlarging mass with tenderness warmth and swelling

Question 17

Multiple Enchondromas

Ollier Disease

Maffucci Syndrome

Answer 17

Associations of Chondromas

Question 18

Diagnostics of Chondromas

Answer 18

found in the metaphysis of tubular bones in hands and feet

Question 19

Morphology of chondromas

Answer 19

well-circumscribed nodules of hyaline cartilage containing cytomorphological benign chondrocytes

sclerotic rim with an intact cortex

usually < 3cm

Grey-blue and translucent

Question 20

Late adolescence- early adulthood

multiple hereditary exostosis syndrome

chondrosarcoma

Answer 20

Osteochondroma associations

Question 21

Most common primary benign bone tumor

Answer 21

Osteochondroma

Question 22

Pathology of Osteochondromas

Answer 22

inactivation of the EXT gene

Question 23

Diagnostics of Osteochondromas

Answer 23

appears at the metaphysis of the bone near the knee

benign cartilage capped tumor that is attached to the underlying skeleton by a bony stalk

Question 24

Morphology of Osteochondromas

Answer 24

Cap is composed of benign hyaline cartilage varying in thickness and has the appearance of a disorganized growth plate

Pedunculated lesion with a bone stalk that is continuous with the cortex and medullary cavity of the underlying bone

underlying stalk contains cancellous

Question 25

Osteochondroma clinical presentation

Answer 25

painful and tender near the ends of long bones

Question 26

2nd most common malignant matrix producing tumor of bone

Answer 26

Chondrosarcoma

Question 27

Predisposing factor of chondrosarcoma

Answer 27

Osteochondroma

Question 28

Diagnostics of Chondrosarcoma

Answer 28

Large bulky tumors of the Axial skeleton nodules of glistening gray-white translucent cartilage

Question 29

Chondrosarcoma morphology

Answer 29

matrix is often gelatinous or myxoid cartilage infiltrates marrow space and surrounds pre-existing bone trabeculae Nuclei often show up and open chromatin pattern with atypia

Question 30

Clinical presentation of chondrosarcoma

Answer 30

painful progressive enlarging masses in the pelvis and axial skeleton usually metastasize to lungs

Question 31

Most common soft tissue tumor of adulthood

Answer 31

Lipoma

Question 32

Features of lipomas

Answer 32

well-encapsulated mass of mature adipocytes usually soft, mobile and painless arises in SubQ of proximal extremities and trunk

Question 33

Pathology of Liposarcoma

Answer 33

t(12;16) causes amplification of 12q13-15 causes mutation in MDM2, disinhibiting p53

Question 34

Pathology of Nodular Fasciitis

Answer 34

t(17;22) produces a MYH9-UPS6 fusion gene

Question 35

Diagnostics of Nodular Fasciitis

Answer 35

usually arises in the deep dermis, SubQ or muscle

Question 36

Morphology of Nodular Fasciitis

Answer 36

usually \< 5cm circumscribed or slightly infiltrative Richly cellular in immature appearing fibroblasts, myofibroblasts, lymphocytes and extravasated RBCs Cells vary in shape and size Cells have conspicuous nucleoli Gradient of maturation from cellular, loose and myxoid to organized fibers

Question 37

Which fibromatosis? Males\> females Dupuytren contracture Peyronie disease

Answer 37

superficial fibromatosis

Question 38

Which fibromatosis? women\> men Gardner Syndrome FAP and APC mutations arise in musculoskeletal aponeurotic structures, limb girdles or mesentery

Answer 38

Deep Fibromatosis "Desmoid Tumor" **due to mutations in APC or Beta Catenin causing increased Wnt signaling**

Question 39

Morphology of fibromatoses

Answer 39

firm, grey-white lesions poorly demarcated masses 1-15cm Tough and rubbery, marked with infiltration of surrounding muscle, nerve and fat cytologically bland fibroblasts are arranged in broad sweeping fascicles amid dese collagen resembles a scar

Question 40

osteoclastoma

Answer 40

tensynovial giant cell tumor

Question 41

Pathology of tensynovial giant cell tumors

Answer 41

neoplastic mononuclear cells produce RANKL to induce osteoclast formation

Question 42

Diagnostics of osteoclastoma

Answer 42

soap bubble lytic lesion surrounded by a thin bony shell, usually around the knee Adults: usually appears at epiphysis or metaphysis Children: usually appears at the metaphysis **XR: multicystic osteolytic lesions**

Question 43

Morphology of Tensynovial Gian Cell Tumor

Answer 43

red-brown mass with cystic degeneration composed of reactive giant cells and neoplastic mononuclear cells

Question 44

Clinical presentation of tensynovial giant cell tumors

Answer 44

local pain and swelling pathologic fractures

Question 45

Associations of fibrous dysplasia

Answer 45

mutations in GNAS1 gene Increased cAMP McCune-Albright Syndrome Mazabraud Syndrome

Question 46

Morphology of Fibrous dysplasia

Answer 46

Gritty, tan-white, well-circumscribed intramedullay mass Curvilinear trabeculae of woven bone surrounded by a moderately cellular fibroblastic proliferation No osteoblastic rim

Question 47

Malignant bone tumor in metaphysis of long bones

Answer 47

Osteosarcoma

Question 48

Malignant cartilage tumor in metaphysis of Axial Skeleton

Answer 48

Chondrosarcoma

Question 49

Malignant cartilage tumor in diaphysis

Answer 49

Chondrosarcoma

Question 50

Malignant bone tumor in the diaphysis of femur, tibia or pelvic bones

Answer 50

Ewing Sarcoma

Question 51

Benign bone tumor in appendicular skeleton

Answer 51

Osteoid Osteoma or Fibrous Dysplasia

Question 52

Benign bone tumor of the metaphysis or epiphysis

Answer 52

Giant Cell Tumor

Question 53

Benign bone tumor in metaphysis of facial bones

Answer 53

osteoma

Question 54

Benign bone tumor in metaphysis of axial skeleton

Answer 54

osteoblastoma

Question 55

Benign cartilage tumor in metaphysis near the knee

Answer 55

osteochondroma

Question 56

Benign cartilage tumor in the metaphysis of tubular bones

Answer 56

Chondroma

Question 57

Benign tumor found in the metaphysis of long bones or posterior vertebral bodies

Answer 57

Aneurysmal Bone Cyst